Security and safety issues capture front-page coverage every day and have a growing impact on the US economy and quality of life. The average US citizen is seriously concerned about his family's risk of exposure to accidents, crime and acts against society.
Infrared (IR) thermal imaging systems have been proliferating in commercial, but mostly industrial and military products. These devices have become less expensive over the last several years but are still too expensive to become mainstream products for widespread consumer use. The need for consumer-priced infrared thermal imaging equipment has never been more pressing. Thermal imaging used on a wide scale allows the US to get a technological edge against those who wish to harm the US.
However, budgetary considerations have created the need for a new generation of Thermal Imaging Sensors. These sensors need to be priced in the commercial rather than scientific or military realm while maintaining the performance of scientific and military devices.
A typical thermal sensor unit (for instance, ¼ VGA) has 320 by 240 resolution=76,800 pixels. These sensor cores cost about $3,000 to $4,000 in lots of 1,000 units. The comparative common denominator is cost per pixel. Using the above example, the cost per pixel is $0.04 per pixel ($3,000/76,800). For true proliferation into consumer markets, the cost per pixel should cost no more than 50¢ per pixel. At that price an imager core (320×240) would cost less than $400 which would be a reasonable base price for consumer products retailing between $1,000 to $2,500. This would amount to 1/10th of what these devices are currently sell for.
The last 40 years have seen the development of many different types of thermal sensors. There are basically two types of detectors: quantum and thermal. In quantum detectors, incoming photons are collected while in thermal detectors, incoming photons are converted to heat which changes some measurable characteristic of the sensor material like resistance or capacitance. Quantum detectors are better but are more difficult to manufacture. However, thermal detectors operate better in the mid to far IR wavelengths of 3 to 14 microns. Furthermore, thermal detector materials operate better at room temperature and do not need active cooling.
Uncooled sensors have received much attention by design engineers as they are smaller, lighter, use less power and cost less. Currently most are bolometers, pyroelectric or thermoelectric. A need therefore exists for a detector that is thermally and electrically isolated from its surroundings and insulated from outside noise sources. Conventional video signal systems create electronic noise from the readout and scanning circuitry.
Thus, a need exists for a low cost thermal imaging device. In particular, a need exists for an efficient method for building a low cost thermal imaging device. A primary purpose of the present invention is to solve these needs and provide further, related advantages.